Because some people can't fathom being paid to do a thing they like, hence "work" is a thing one has to do to enable the things they like to do. This is very sad, but not because these people, but because people have to do things they don't like at all, just to exist.

Then, there is this arbitrary line in the sand between work and things like volunteering.

I have a well paying job as a swe for a company. I also volunteer for my sailing clubs for various things. I get paid in both cases. For my swe job via moneis and other perks. For my sailing clubs by providing some services today, so someone else can go sailing and they'll do the same next week. Still work, different pay.

my rationale is the odds of a relationship not working out are substantially higher than it will. Also, there is a relatively low chance I will still want to see my ex after a breakup. So I try my hardest not to see my coworkers as romantic options. It’s not easy, but I feel like it helps keep things professional in the workplace.